Common Ticks Responsible for Disease Transmission
Amblyomma americanum
Common Name: Lone Star Tick
Where Found: Widely distributed in the southeastern and eastern United States.
Transmits: Ehrlichia chaffeensis and Ehrlichia ewingii (which cause human ehrlichiosis), Heartland virus, tularemia, and STARI.
Comments: A very aggressive tick that bites humans. The adult female is distinguished by a white dot or “lone star” on her back. Lone star tick saliva can be irritating; redness and discomfort at a bite site does not necessarily indicate an infection. The nymph and adult females most frequently bite humans and transmit disease.
Lone Star Tick: CDC/ Michael L. Levin, Ph. D.
Amblyomma maculatum
Common Name: Gulf Coast Tick
Where Found: Coastal areas of the U.S. along the Atlantic coast and the Gulf of Mexico.
Transmits: Rickettsia parkeri rickettsiosis, a form of spotted fever.
Comments: Larvae and nymphs feed on birds and small rodents, while adult ticks feed on deer and other wildlife. Adult ticks have been associated with transmission of R. parkeri to humans.
Gulf Coast Tick: CDC/ Dr. Christopher Paddock
Dermacentor Andersoni
Common Name: Rocky Mountain Wood Tick
Where Found: Rocky Mountain states, northern Arizona, and southwestern Canada from elevations of 4,000 to 10,500 feet.
Transmits: Rocky Mountain spotted fever, Colorado tick fever, and tularemia.
Comments: Adult ticks feed primarily on large mammals. Larvae and nymphs feed on small rodents. Adult ticks are primarily associated with pathogen transmission to humans.
Rocky Mountain Wood Tick: CDC/ Dr. Christopher Paddock
Dermacentor variabilis
Common Name: American Dog Tick
Where Found: Widely distributed east of the Rocky Mountains. Also occurs in limited areas on the Pacific Coast.
Transmits: Tularemia and Rocky Mountain spotted fever.
Comments: The highest risk of being bitten occurs during spring and summer. Dog ticks are sometimes called wood ticks. Adult females are most likely to bite humans.
American Dog Tick: CDC/DVBID/ Gary O. Maupin
Ixodes scapularis
Common Name: Black-legged Tick
Where Found: Widely distributed across the eastern United States.
Transmits: Borrelia burgdorferi and B. mayonii (which cause Lyme disease), Anaplasma phagocytophilum (anaplasmosis), B. miyamotoi disease (a form of relapsing fever), Ehrlichia muris eauclairensis (ehrlichiosis), Babesia microti (babesiosis), and Powassan virus (Powassan virus disease).
Comments: The greatest risk of being bitten exists in the spring, summer, and fall. However, adults may be out searching for a host any time winter temperatures are above freezing. Stages most likely to bite humans are nymphs and adult females.
Black-legged Tick: CDC/ Michael L. Levin, PhD
Ixodes pacificus
Common Name: Western Black-legged Tick
Where Found: Along the Pacific coast of the U.S., particularly northern California.
Transmits: Anaplasmosis and Lyme disease.
Comments: Nymphs often feed on lizards, as well as other small animals. As a result, rates of infection are usually low (~1%) in adults. Stages most likely to bite humans are nymphs and adult females.
Western Black-legged Tick: CDC/ James Gathany; William L. Nicholson, Ph.D.
Rhipicephalus Sanguineus
Common Name: Brown Dog Tick
Where Found: Worldwide.
Transmits: Rocky Mountain spotted fever (in the southwestern U.S. and along the U.S.-Mexico border).
Comments: Dogs are the primary host for the brown dog tick in each of its life stages, but the tick may also bite humans or other mammals.
Brown Dog Tick: CDC/ James Gathany; William Nicholson
Further information on ticks and the diseases they spread, as well as the information provided in this page can be found at: https://www.cdc.gov/ticks/index.html